Poly 6521901 Replacement Headset

Plantronics S12 replacement/spare headset. This Headset comes with a "firefly" in-use busy light at tip of microphone. This headset plugs directly into Plantronics S12 base with modular (square) plug. This headset is the replacement for your existing S12 system only. It will NOT work with any other Plantronics amplifier.